Ship name????

[maryd]

Does anyone know how I can find out the name of a ship on which my grandparents travelled to South Africa in either late 1918/9 or early 1920's please. I know they did not stay long and that they eloped to be married before travel. I have their marriage cert from Norwich - they eloped from Whitehaven in Cumbria so it was a long journey, and they may have travelled directly to London/ Harwich....they definitely stayed in Madeira. Help would be seriously appreciated....many thanks.

Mary